1. Field of the Invention
The present invention pertains to a well liner running shoe which includes a check valve, cement plug receiver, and running tool receiver for operation with standard cement plugs and running tools. The running shoe is used to set well liners without requiring a liner hanger.
2. Background
In certain well operations, the wellbore is extended beyond the previous bottom or cased portion by inserting an extension of the casing or liner and hanging the liner off of the top end thereof by a hanger assembly which is engaged with the lower end of the casing previously extended into the wellbore. Such liner hangers are relatively expensive and, in relatively shallow wells which are, from time to time, extended deeper, the installation of a liner with a liner hanger is an expensive procedure. An alternate method involves extending the liner into the wellbore with a running tool and then cementing the liner in place by pumping cement through a shoe connected to the bottom of the liner. This arrangement is more economical and holds certain advantages, for setting liners on the bottom of a well, in particular.
However, there has been a need for providing certain improvements in liner running and setting using a running tool followed by a cementing procedure including the provision of a shoe which includes a check valve, a positive stop or separating member for running the cement into its final placement and while still having characteristics which will permit drilling out the shoe in the event that it is desired to extend the well even deeper.
The present invention provides certain improvements in apparatus and a method for setting well liners, particularly at the bottom of a well, without using a liner hanger but while employing a unique running shoe and setting method.